Aviationinfo Posted October 19, 2016 Report Posted October 19, 2016 I'm thinking a full on OH is not required for Part 91 operations either. Just like engine overhauls. That's why we can replace cylinders (or not) and blow right past the TBO. Pretty sure it's a different story for 135 ops though.
Shadrach Posted October 19, 2016 Author Report Posted October 19, 2016 1 hour ago, Aviationinfo said: I'm thinking a full on OH is not required for Part 91 operations either. Just like engine overhauls. That's why we can replace cylinders (or not) and blow right past the TBO. Pretty sure it's a different story for 135 ops though. You're right, but many prop shops don't want their name on a prop that is operated outside of the manufacturer's recommendations. I was going to try and find someone to IRAN it, but the cost delta between IRAN (reseal) and OH was small; in fact, some folks wanted north of $2K for reseal. $1895 to overhaul a CS Hartzell is beyond reasonable.
Cody Stallings Posted October 20, 2016 Report Posted October 20, 2016 Wow!!! $2K for a Reseal!!! I would be run out of business for charging that. Also, keep in mind the O/H is much more evasive than an IRAN. When I say that, lots of aluminum is removed from the blades. Not good if it doesn't warrant the work.
Shadrach Posted October 20, 2016 Author Report Posted October 20, 2016 43 minutes ago, Cody Stallings said: Wow!!! $2K for a Reseal!!! I would be run out of business for charging that. Also, keep in mind the O/H is much more evasive than an IRAN. When I say that, lots of aluminum is removed from the blades. Not good if it doesn't warrant the work. I agree. How many overhauls will a prop typically withstand?
Andy95W Posted October 20, 2016 Report Posted October 20, 2016 1 hour ago, Cody Stallings said: Wow!!! $2K for a Reseal!!! I would be run out of business for charging that. Also, keep in mind the O/H is much more evasive than an IRAN. When I say that, lots of aluminum is removed from the blades. Not good if it doesn't warrant the work. Just out of curiosity, about how much blade material gets removed at each O/H? What are some sample minimum dimensions on my Hartzell prop?
Cody Stallings Posted October 20, 2016 Report Posted October 20, 2016 Well it's different with each prop. Your Basic Hartzell 2 way with F7666A-2 blade has a lot of blade width, so if damage between O/H's is minimal an the A&P are easy with the files during annual, you can expect to see 4-5 O/H's. However the 3 way Hartzell with F7282 blades, is a Much thinner blade. 2-3 O/H's are to be expected with normal wear an tear. 3
Cody Stallings Posted October 20, 2016 Report Posted October 20, 2016 36 minutes ago, N1395W said: Just out of curiosity, about how much blade material gets removed at each O/H? What are some sample minimum dimensions on my Hartzell prop? I would have to have your blade design before I could produce the manufactures minimums. Just the grinding an polishing of the blade will remove 15-20 thousands off both face an camber sides of the blade. So 40 off ,when on certain designs only have 90-110 between New Deminsion and Scrap Deminsion. Wanna be conservative with that blade material, only wanna take off what you have to. Nothing more. 2
Andy95W Posted October 20, 2016 Report Posted October 20, 2016 Thanks, Cody. I always assumed blade width (from over dressing nicks) was the problem, but it's actually blade thickness. Good information!
Shadrach Posted October 20, 2016 Author Report Posted October 20, 2016 2 hours ago, N1395W said: Thanks, Cody. I always assumed blade width (from over dressing nicks) was the problem, but it's actually blade thickness. Good information! I think it's a combination of all the above. I'm certain there is a minimum blade width.
Guest Posted October 20, 2016 Report Posted October 20, 2016 18 hours ago, Cody Stallings said: I would have to have your blade design before I could produce the manufactures minimums. Just the grinding an polishing of the blade will remove 15-20 thousands off both face an camber sides of the blade. So 40 off ,when on certain designs only have 90-110 between New Deminsion and Scrap Deminsion. Wanna be conservative with that blade material, only wanna take off what you have to. Nothing more. Cody, After the paint is stripped from the blades, I would have thought that polishing would be in order more than grinding or sanding the blades. Are they really that badly damaged? Clarence
Cody Stallings Posted October 21, 2016 Report Posted October 21, 2016 Yes, every blade design has a minimum width an thickness. After the paint comes off it's tells the story of the condition of the blade. With O/H all damage has to be removed from the blades, an yes that takes a lot of grinding. After the grind is complete you have to polish it to remove the grinding marks left behind. In most cases there is much more damage in the blade that can be seen with the paint removes. Might not be deep rock nicks, but it all has to come out to comply with the O/H Manuel's 1
Raptor05121 Posted October 21, 2016 Report Posted October 21, 2016 Cody, I am very appreciative to have your insight on here. Lot's to learn! 1
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